Alan Hale

Comet Hale-Bopp

long-period comet that was spectacularly visible to the naked eye, having a bright coma and a thick white dust tail. It was discovered independently in July 1995 by Alan Hale and Thomas Bopp, two American amateur astronomers, at the unusually far distance of 7 astronomical units (AU; about 1 billion km [600 million miles]) from the Sun, well beyond Jupiter’s orbit. The comet reached perihelion...